1. Field of the Invention
This invention relates to prosthetic heart valve assemblies, and more specifically to a unique center-flow occluder of such assemblies.
2. Description of the Prior Art
It is known in the prior art to replace a diseased defective valve in the human heart with a prosthetic, or artificial heart valve assembly. In many cases, a patient has continued to live for many years with such a prosthetic heart valve assembly.
Prosthetic heart valve assemblies which most closely approximate the action of natural heart valves are of the center-flow type. Specifically, these prosthetic heart valve assemblies include an elongate occluder which is movable between closed and opened positions within a seating-ring passage of a valve seat assembly. The occluder includes a plurality of cuspids which are movable radially which respect to each other between a closed condition when the occluder is in a closed position, and an opened condition when the occluder is in an opened position. When the cuspids are in their opened condition blood can flow through the interior thereof to simulate the action of a natural heart valve.
The center-flow occluders disclosed in prior art prosthetic heart valve assemblies preferably are formed of a plastic material, such as polypropylene, since such a material is generally lightweight and easily formable into the desired configuration for use in heart valve assemblies. It has been discovered that these center-flow occluders, and particularly the cuspids thereof, become deformed after continued usage. Deformation of the cuspids prevents the occluder from effectively sealing the opening through the valve seat assembly when the occluder is in its closed position. This ineffective sealing of the heart valve assembly causes an undesirable leakage of blood through the seating-ring passage.